Hi mate,
With regards to the Anemone, IF you were setting up a new tank, then fine; start tank, once it is ready for the nem, add it and get your flow correct and finalised for how you want it for the SPS. Let the nem find its place...it aint necessarily going to be where you want it to stay.
Anyway, once it is settled, you can add the SPS etc. But from this point on, any major change like an upgrade to the lighting or flow can annoy then nem causing it to go round looking for somewhere else nice to sit its butt.
So, yes, many people do have nems in an SPS tank, but usually start off with one...hence FAR less chance of it moving later.
I would love to keep one...I see so many nice ones at the LFS, but never take the chance.
With regards to your tank; I was about to ask you to take out the GFO, or at least half the amount you have in the tank.
I recall you are using Rowaphos? - That stuff is very efficient and fast acting and hence I never use it.
You wont believe it, but I have about 1 litre of GFO in my sump right at this moment.
However: it is a VERY SLOW acting GFO. I have more than 0.5 litre in a bag with slow water running over it. I also have slightly less than 0.5 litre in a reactor...the flow for the reactor has been T'd off the return pump and I am only running about 10 litres per hour through that reactor. So fairly slow flow.
Note that I didnt add all of it at once, but slowly over weeks and weeks added more. The stuff in the bag is the oldest, and it will be chucked out in a few months.
I am only using the GFO to keep PO4 enough to keep algae controlled. When I upgrade to a large cube I will utilise a whole lot more biological algae control like fishes and urchins etc.
So does this mean you are going to stop using GFO? Or are you simply going to stop measuring PO4 and use a small amount and change out monthly etc?
Sorry about the continued issues you are having.